Safety device for automobile vehicles and the like

ABSTRACT

The starter switch of an automobile vehicle is series connected to the ignition coil via a thyristor, and is connected, via delay means and a second contact of coupled switch, to a monitor device for producing a perceptible signal after a variable time interval from actuating the starter switch. Said delay means simultaneously supplies the base of a transistor via an R-C timeconstant, the collector-emitter lead of this transistor being connected to the control line of the thyristor via the first contact of said coupled switch. Said contacts are coupled so that when one is open, the other is closed whereby when the starter switch is actuated whilst the second contact is closed and the first contact open, the ignition coil is excited if the second switch is actuated within a selected time interval after production of said signal.

United States Patent 1 Rochat [451 July 31,1973

SAFETY DEVICE FOR AUTOMOBILE VEHICLES AND THE LIKE Freddy Rochat, 1341Vers-Chez-Grosjean, Vaud, Switzerland Filed: Nov. 30, 1971 Appl. No.:203,371

Inventor:

Foreign Application Priority Data Dec. 1, 1970 Switzerland 17811/70References Cited UNlTED STATES PATENTS Primary Examiner-Robert K.Schaefer Assistant ExaminerWilliam J. Smith Attorney-Raymond A. RobicABSTRACT The starter switch of an automobile vehicle is series connectedto the ignition coil via a thyristor, and is connected, via delay meansand a second contact of coupled switch,to a monitor device for producinga perceptible signal after a variable time interval from actuating thestarter switch. Said delay means simultaneously supplies the base of atransistor via an R-C time-constant, the collector-emitter lead of thistransistor being connected to the control line of the thyristor via thefirst contact of said coupled switch. Said contacts are coupled so thatwhen one is open, the other is closed whereby when the starter switch isactuated whilst the second contact is closed and the first contact open,the ignition coil is excited if the second switch is actuated within aselected time interval after production of said signal.

6 Claims, 1 Drawing Figure PATENIEDJULIN ms V .lllll' ll.

SAFETY DEVICE FOR AUTOMOBILE VEHICLES AND THE LIKE BACKGROUND AND OBJECTOF THE INVENTION It is an object of the invention to provide a device bymeans of which the starting up of, for example, an automobile vehiclemotor can be subordinated to the driver having a desired reflex action,so that persons in a state of drunkenness or any other physical statewhich impairs their relfeces cannot start up the motor, and aretherefore prevented from driving the vehicle.

SUMMARY OF THE INVENTION This object can be achieved by providing thevehicle ignition circuit with means for only allowing feed of theignition coil by the successive actuation of two switches, namely theconventional ignition or starter switch and a supplementary switch,actuation of this supplementary switch being effective to close theignition circuit only during a selected interval of time after aperceptible signal, for example optical or acoustic.

According to one aspect of the invention, a safety'device for anapparatus of the above mentioned kind comprises a manually actuatablefirst switch-means for producing a perceptible signal after a certaintime interval from actuating said first switch, a manually actuablesecond switch, and circuit means for actuating said sarting means onlywhen the second switch is actuated within a selected interval of timeafter production of said perceptible signal.

Preferably, the means for producing the perceptible signal produce saidsignal after a variable time interval from actuating said switch.

In a preferred embodiment of the invention, a safety device forautomobile vehicles, in which the feed circuit for the primary windingof the ignition coil comprises, in series with a manually actuableignition switch, a thyristor whose control circuit is fed, via a firstcontact of a manually actuable coupled switch with coupled first andsecond contacts arranged such that when one of said first and secondcontacts is open the other is closed, by the emitter-collector lead of afirst transistor whose base is itself fed with a time constant by theemitter-collector lead of a second transistor,

which lead is provided on the one hand with the'second contact of thecoupled switch, and on the other hand with a monitor device forproducing a perceptible signel, the base of said second transistor beingfed with a time constant by the current source when the manual ingitionswitch is closed, said circuit also comprising a second thyristor fed bythe emitter-collector of the first transistor and whose control circuitis directly connected to the emitter-collector line of the firsttransistor, this second thyristor actuating a relay controlling a thirdcontact located in the base lead of the first transistor. In operation,when the manual ignition switch is closed, whilst the coupled switch hasits first contact open and its second contact closed, the monitor deviceproduces a perceptible signal after a timedetermined by the timeconstant with'which the second transistor is fed, the base of the firsttransistor being fed at the same time as said monitor device, such thatafter a time determined by the time constant with which the base of thefirst transistor is fed the first thyristor operates providing thatmeanwhile, that is after appearance of the signal produced by themonitor device, the'coupled switch has been actuated to close said firstcontact and enable the control line of said first thyristor to be fed,operation of said first thyristor producing feed of the primary windingof the ignition coil, which enables starting up of the motor. However,if the coupled switch'is not actuated in time, the first thyristor doesnot operate which prevents starting up of the motor, the secondthyristor, whose control lead is fed as soon as the second transistorsupplies an impulse, actuating the relay which opens the third contactthus breaking the supply to the base of the first transistor, whichprevents said first transistor from supplying anew impulse which wouldrepeat the operation, the second contact of the coupled switch locatedin the emitter-collector line of the second transistor preventing thesecond switch from being operated in advance, that is before the signalis produced, because the second contact is broken when this switch isopened, thus preventing the emitter-collector lead of the secondtransistor from supplying the monitor device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The single FIGURE ofthe accompanying drawing shows, by way of example, the circuit diagramof the preferred embodiment of device according to the invention, forapplication to an intemalcombustion engine motor vehicle.

The circuit comprises a current source 1, namely the battery of theautomobile vehicle, connected in series with a primary winding 2 of thevehicles ignition coil, and a conventional ignition or starter switch 3.

Feed of the winding 2 from the output terminal of the switch 3 takesplace through a thyristorTh, connected in series and whose control line4 is connected, via the contact Ct of a coupled two-contact manualcontrol switch, to the emitter-collector lead 5 of a first unijunctiontransistor T The base BT of transistor T is fed, with aresistor-capacitor time-constant comprising a resistor R and a capacitorC by a lead 6 connected to the base of a second transistor T, with anemittercollector lead 7.

A contact 8 controlled by a relay R is connected in series in the supplylead 6 of the base BT of transistor T This relay R is actuated by asecond thyristor Th,, fed by the lead 6, and whose control lead 9 isdirectly connected to the emitter-collector 5 of the first transistorT,. I

V The emitter-collector lead 7 of the second transistor T, comprises, inseries, a monitor light LT and the second contact Cr, of the coupledmanual switch comprising the contact Ct,, as indicated in dashed lines10. These contacts Ct and Cr, are coupled such that when one is open theother is closed.

The base RT, of transistor T, is fed by the current source 1, when theignition switch 3 is closed, with a resistor-capacitor time-constantcomprising a resistor R,

I (which is a thermistor, as described later on) and a capacitor C,,. AZener diode D serves to maintain a constant voltage for charging thecapacitor C,.

In operation, to start the vehicle the driver closes the ignition switch3, which has the effect of charging the capacitor C, with thetime-constant R, --C,. Initially,

the contact Ct, of the coupled switch is closed whilst the contact Ct,is open and the contact 8, controlled by the relay R, is closed.

After a lapse of time determined by the time-constant R, C,, thetransistor T becomes conducting and the monitor lamp LT lights up toprovide a visual signal perceptible to the driver, at the same time asthe lead 6 is fed.

The capacitor C, thus charges up with the timeconstant R, -C, whichdetermines the lapse of time after which the unijunction transistor T,produces an impulse capable of triggering the two thyristors Th, and

If, in the meantime, the coupled manual switch actuating the twocontacts Ct, and Ct, has been operated, the contact Ct, is thus closedand the thyristor Th, can operate, thus feeding the primary winding 2 ofthe ignition coil, which enables starting of the motor.

If, to the contrary, said coupled switch has not been operated withinsaid lapse of time, the contact Cl, is open at the moment when thetransistor T, emits its impulse, so that the thyristor Th, does notoperate and the primary winding of the ignition coil is thus not fed.

The. thyristor Th, operates,- whatever be the position of the contactC1,, and actuates the relay R to open contact 8. It is thus not possiblefor the capacitor C, to recharge so that the transistor T, is preventedfrom emitting a new impulse directly after the first.

Moreover, operation of the coupled switch not only closes the contactCt,, but also opens the contact Ct, Consequently, it would be futile forthe driver to try and operate the said coupled switch in advance, thatis before the monitor lamp LT lights up. In effect, opening of thecontact Ct, cuts the emitter-collector lead 7 of the transistor T, andthus makes actuation of the transistor T without effect on the lamp LT.

The device also comprises mechanical means, not shown, for the momentarymanual closing of the contact 8 normally closed by the relay R,so as toenable the driver to carry out further attempts to start the motor. Ofcourse, said mechanical means would not enable the contact 8 to be heldpermanently closed.

The resistor R, is a thermistor with high temperature sensitivity sothat the time-constant R -C, varies as a function of the ambienttemperature. The time interval between the moment when the driver closesthe ignition switch 3 and when the monitor lamp LT lights up thusvaries, so that the driver cannot'become used to this interval andtherefore acquire a conditionned reflex which could enable him to startthe motor whilst he was in a deficient physical state. Of course, othermeans could be employed for varying the delay in producing theperceptible signal.

As a variant, the optical indicator formed by the monitor lamp LT couldbe replaced by other means for producing a perceptible signal, forexample an acoustic indicator producing sound signals.

What is claimed is:

1. Safety device for manually operable apparatus such as an automobilevehicle, which apparatus comprises electrically actuable starting meansand requires a desired reflex action by an operator for the satisfactoryoperation thereof, said device comprising a manually actuatable firstswitch, means for producing a perceptible signal after a certain timeinterval from actuating said first switch, a manually actuable secondswitch, circuit means for actuating said starting means only when thesecond switch is actuated within a selected interval of time afterproduction of said perceptible signal, a first thyristor connected inseries between said first switch and said starting means, the controllead of said thyristor being connected in series via a first contact ofsaid second switch with the emitter-collector lead of a firsttransistor, the base of said first transistor being fed via a first R-Ctime-constant by the emittercollector lead of a second transistor, saidemittercollector lead of the second transistor also controlling via asecond contact of said second switch a device for producing aperceptible signal, the base of said second transistor being connectedin series with a second R-C time-constant with said first switch, thefirst and second contacts of said second switch being coupled so thatwhen one of said first and second contacts is open the other is closed.

2. Device according to claim 1, comprising a second thyristor connectedto the emitter-collector lead of said first transistor, and a relaycontrolling a third contact in the base lead of the first transistor.

3. Device according to claim 2, comprising means for non-permanentlymanually closing said third contact.

4. Device according to claim 1, in which said second R-C time-constantcomprises a thermistor.

5. Device according to claim 1, in which said first transistor is aunijunction transistor.

6. Device according to claim 1, comprising a Zener diode in the feedlead to the base of said second transistor.

1. Safety device for manually operable apparatus such as an automobilevehicle, which apparatus comprises electrically actuable starting meansand requires a desired reflex actioN by an operator for the satisfactoryoperation thereof, said device comprising a manually actuatable firstswitch, means for producing a perceptible signal after a certain timeinterval from actuating said first switch, a manually actuable secondswitch, circuit means for actuating said starting means only when thesecond switch is actuated within a selected interval of time afterproduction of said perceptible signal, a first thyristor connected inseries between said first switch and said starting means, the controllead of said thyristor being connected in series via a first contact ofsaid second switch with the emitter-collector lead of a firsttransistor, the base of said first transistor being fed via a first R-Ctime-constant by the emitter-collector lead of a second transistor, saidemittercollector lead of the second transistor also controlling via asecond contact of said second switch a device for producing aperceptible signal, the base of said second transistor being connectedin series with a second R-C time-constant with said first switch, thefirst and second contacts of said second switch being coupled so thatwhen one of said first and second contacts is open the other is closed.2. Device according to claim 1, comprising a second thyristor connectedto the emitter-collector lead of said first transistor, and a relaycontrolling a third contact in the base lead of the first transistor. 3.Device according to claim 2, comprising means for non-permanentlymanually closing said third contact.
 4. Device according to claim 1, inwhich said second R-C time-constant comprises a thermistor.
 5. Deviceaccording to claim 1, in which said first transistor is a unijunctiontransistor.
 6. Device according to claim 1, comprising a Zener diode inthe feed lead to the base of said second transistor.